[patch, x86] Improve memcpy/memset strategy for Skylake.

[Koval, Julia]

Hi,
This patch improves memset/memcpy strategy for Skylake. Ok for trunk?

        * gcc/config/i386/x86-tune-costs.h (skylake_memcpy,
        skylake_memcpy): Replace rep_prefix with unrolling on 512.

Thanks,
Julia

0001-memset.patch
Description: 0001-memset.patch